Warm-up times of CFL & tubular fluorescent

[Alex Coleman]

I have read that a CFL take a few minutes to warm up.

Is there any change in output, colour temperature ,etc between a "few
minutes" and 10 minutes? 20 minutes? 30 minutes? 60 minutes?

Does tubular fluorescent share these characteristics or does tubular
warm up and reach its peak (output, colour temp, etc) so rapidly that
after a minute or two it is not going to change?

I am on 230V here in the UK.

 

[Victor Roberts]

I have read that a CFL take a few minutes to warm up.

Is there any change in output, colour temperature ,etc between a "few
minutes" and 10 minutes? 20 minutes? 30 minutes? 60 minutes?

Yes, changes can occur for up to 60 minutes, but 30 minutes
is more common. The major changes are over in a "few
minutes" but after that there can be slow drift that is most
easily seen with a meter.

Does tubular fluorescent share these characteristics or does tubular
warm up and reach its peak (output, colour temp, etc) so rapidly that
after a minute or two it is not going to change?

Tubular fluorescent lamps do reach thermal equilibrium more
quickly that CFLs. But there can still be small changes for
15 to 20 minutes. It all depends upon how small a change
you are looking for. And, all fluorescent will vary when
the ambient temperature changes.

I am on 230V here in the UK.

Shouldn't matter.

--
Vic Roberts
http://www.RobertsResearchInc.com
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[Andrew Gabriel]

I have read that a CFL take a few minutes to warm up.

Is there any change in output, colour temperature ,etc between a "few
minutes" and 10 minutes? 20 minutes? 30 minutes? 60 minutes?

Does tubular fluorescent share these characteristics or does tubular
warm up and reach its peak (output, colour temp, etc) so rapidly that
after a minute or two it is not going to change?

Tubular fluorescents share these characteristics, but the
scale is different. Compact fluorescents are often designed
to run at 100C verses 40C of old linear fluorescent tubes,
so there's a bigger ratio between initial room temperature
and the operating lamp temperature. This means that when
switched on initially, compact fluorescents are further
away from their eventual operating parameters, and thus
the mercury vapour pressure is further away from its
final operating pressure, and the light output is more
severely affected. Conversely, old linear fluorescent
tubes take much longer to run up (Thorn Lighting Technical
Handbook specifies about 20 minutes), but the run up is
often unnoticed because it takes a long time and the light
output change is not as dramatic as with a compact fluorescent.

I am on 230V here in the UK.

So am I ;-)

 

[TKM]

Tubular fluorescents share these characteristics, but the
scale is different. Compact fluorescents are often designed
to run at 100C verses 40C of old linear fluorescent tubes,
so there's a bigger ratio between initial room temperature
and the operating lamp temperature. This means that when
switched on initially, compact fluorescents are further
away from their eventual operating parameters, and thus
the mercury vapour pressure is further away from its
final operating pressure, and the light output is more
severely affected. Conversely, old linear fluorescent
tubes take much longer to run up (Thorn Lighting Technical
Handbook specifies about 20 minutes), but the run up is
often unnoticed because it takes a long time and the light
output change is not as dramatic as with a compact fluorescent.

There can be phosphor differences between CFLs and linear fluorescent lamps
too. It's common, for example, for CFLs to use the blue emissions from the
arc for the blue output of the lamp; no so for linear lamps.

Terry McGowan